This paper studies a very particular use of emojis on WhatsApp: the substitution or reproduction of a term by means of its visual representation. Using a qualitative approach, a corpus of WhatsApp messages is analyzed, identifying regularities in the use of emojis to replace or emphasize words, and the possible mechanisms of visual transposition. Emojis can supplant or visually repeat nouns, verbs, adjectives, interjections and more complex expressions. When lacking a specific emoji, users employ metonymy to offer a rough visual representation of the term sought or make reference to social imaginary. The paper also shows that emojis may reproduce stereotypes and biases of our society.